?1.relative_identifier(
  ?2,
  key: ?3
)
?1.relative_identifier(
  ?2,
  key: ?3
)(
  ?4,
  key: ?5
)
?1.relative_identifier key: ?2
?1.relative_identifier unqualified ?2,
                                   key: ?3
?1.relative_identifier ?2,
                       key: ?3